After much deliberation, I decided I needed the rest more than I needed shots of the sunset. And I'm really happy I didn't go out to get them because what started off as a beautiful day ended in being overcast just around the time of sunset. So, I secretly lauded myself for prioritizing on my rest.
I coaxed my son into sitting for me again this evening, because I wanted to try cross-lighting with my flashes. I set up one flash at 45 deg behind the subject to camera left as the rim light, and used my diffuser on the other flash that I had on camera.
Most disappointingly, my on-camera flash gave out after I'd just taken the first 3 or 4 shots. I am not sure whether it was the batteries that caused the problem, or if it was the flash itself. I am keeping my fingers crossed that it isn't my flash - I've been having trouble with the mechanics from day 1. The locks on the shoe-mount are really hard to turn, and the flash just doesn't sit properly on my camera's shoe-mount either, giving me enough cause to freak out at every sudden movement of the camera.
This first image was done with the cross-lighting set up as I've mentioned earlier. I had set it to 1/8 power and 85 mm zoom, to get a narrower beam of light. My on-camera flash was set at 1/2 power, as this was my key light, and I had the diffuser on it as well. Further, I bounced the flash off the ceiling. I kept the shutter down to 1/60s to be able to get the ambient overhead light as well. This created a hint of shoulder light on the left shoulder of the subject, but I would have like it to be more pronounced, so the separation would be clearer.
The image below was taken with only a single light set-up after one of my flashes malfunctioned. I side-bounced the flash on the wall to the right of camera and used a white foam core board to the right of the subject (left of camera) as reflector to fill in the shadows a little bit. It didn't do a fabulous job as the reflector was at least 6 ft away from the wall, but it was better than when I used no reflector at all.